Tire

Abstract

This tire includes: a plurality of first shallow grooves that have a groove depth which is smaller than the sipe depth of a first sipe and the sipe depth of a second sipe, that extend in a first direction, and that cross the second sipe; and a plurality of second shallow grooves that have a groove depth which is smaller than the sipe depth of the first sipe and the sipe depth of the second sipe, that extend in a second direction, and that cross the first sipe.

Description

tire

[0001] The present invention relates to a tire.

[0002] Conventionally, winter tires have been proposed in which blocks are provided with multiple sipes and multiple shallow grooves that are shallower than the sipes (for example, Patent Document 1). With such tires, the shallow grooves remove water film, ensuring the same performance on snow and ice as when the tire was new.

[0003] Japanese Patent Application Laid-Open No. 2004-034903

[0004] In the above-mentioned technologies, there is still room for improvement in terms of grip performance on ice.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a pneumatic tire with improved grip performance on ice.

[0006] The gist of the present invention is as follows: (1) A tire provided with a land portion partitioned by a first circumferential groove extending in the tire circumferential direction and a second circumferential groove extending in the tire circumferential direction, wherein the land portion is formed with: a first oblique widthwise groove extending in a first direction oblique with respect to the tire width direction, a second oblique widthwise groove extending in a second direction oblique with respect to the tire width direction on the opposite side to the first oblique widthwise groove, a first sipe extending in the first direction, and a second sipe extending in the second direction, wherein the first oblique widthwise groove, a plurality of the first sipes, the second oblique widthwise groove, and a plurality of the second sipes are repeatedly formed in the tire circumferential direction, and a plurality of first shallow grooves having a groove depth smaller than the sipe depth of the first sipe and the sipe depth of the second sipe, extending in the first direction, and intersecting with the second sipes; the tire further comprises a plurality of second shallow grooves having a groove depth smaller than the sipe depth of the first sipes and the sipe depth of the second sipes, extending in the second direction, and intersecting the first sipes.

[0007] In this specification, the terms "first circumferential groove," "second circumferential groove," "first oblique widthwise groove," and "second oblique widthwise groove" refer to grooves with a groove width (opening width) of 2 mm or more, and the term "sipe" refers to a sipe width that is such that it is partially closed when the tire is in contact with the ground, for example, a sipe width of 0.3 mm or more and 0.6 mm or less. The "depth" of a sipe or shallow groove refers to the maximum depth when the pneumatic tire is mounted on an applicable rim, inflated to the specified internal pressure, and no load is applied.

[0008] In this specification, the term "applicable rim" refers to the standard rim (referred to as "Measuring Rim" in the ETRTO STANDARDS MANUAL and "Design Rim" in the TRA YEAR BOOK) for the applicable size, which is an industrial standard valid in the region where the tire is produced and used, and which is described in the JATMA YEAR BOOK of the Japan Automobile Tire Manufacturers Association (JATMA) in Japan, the STANDARDS MANUAL of the European Tire and Rim Technical Organization (ETRTO) in Europe, and the YEAR BOOK of the Tire and Rim Association, Inc. (TRA) in the United States, or which will be described in the future. "rim" refers to the tire's width corresponding to the tire's bead width (i.e., the "rim" in the above "wheel" includes not only current sizes but also sizes that may be included in the above industry standards in the future. Examples of "sizes to be described in the future" include sizes listed under "FUTURE DEVELOPMENTS" in the 2013 edition of ETRTO). However, for sizes not listed in the above industry standards, it refers to a rim with a width corresponding to the tire's bead width. Furthermore, "specified internal pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity of a single wheel in the applicable size / ply rating listed in the above JATMA etc., and for sizes not listed in the above industry standards, "specified internal pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity specified for each vehicle on which the tire is mounted. Furthermore, "maximum applied load" described below refers to the load corresponding to the above maximum load capacity.

[0009] According to the present invention, a pneumatic tire with improved grip performance on ice can be provided.

[0010] 1 is a development view showing a tread pattern of a tire according to an embodiment of the present invention; FIG. 2 is a diagram for explaining an example of an arrangement of a communication device;

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0012] 1 is a development view showing a tread pattern of a tire according to one embodiment of the present invention. The internal structure of the tire is not particularly limited, but according to convention, the tire may include a pair of bead portions, a pair of sidewall portions connected to the bead portions, and a tread portion connected to the sidewall portions. Furthermore, the tire may include a carcass toroidally spanning the pair of bead portions, and a reinforcing layer such as a belt on the radially outer side of the crown portion of the carcass.

[0013] As shown in Figure 1, this tire has a tread surface 1 with a plurality of circumferential grooves 2 extending in the tire circumferential direction, and a plurality of land portions 3 are defined between the circumferential grooves 2 or between the circumferential grooves 2 and the tread edge TE. Here, the "tread surface" refers to the entire surface in the tire circumferential direction of the contact surface that comes into contact with the road surface when the pneumatic tire is mounted on an applicable rim, inflated to a specified internal pressure, and subjected to a maximum load.

[0014] In the illustrated example, four circumferential grooves 2 are formed, with circumferential grooves 2a and 2b located in one half of the tire width direction bounded by the tire equatorial plane CL, and circumferential grooves 2c and 2d located in the other half of the tire width direction bounded by the tire equatorial plane CL. The number of circumferential grooves 2 is not limited to four and may be two or more. In the illustrated example, all circumferential grooves 2 extend straight in the tire circumferential direction, but they may also extend in a zigzag, bent, or curved shape. In the illustrated example, the circumferential grooves 2 extend in the tire circumferential direction (without inclination), but they may also extend at an inclination angle of 5° or less with respect to the tire circumferential direction. The groove width (opening width) of the circumferential grooves 2 may be, for example, 2 mm to 12 mm. The groove depth (maximum depth) of the circumferential grooves 2 may be, for example, 5 mm to 12 mm. In this embodiment, the circumferential groove 2b is referred to as a "first circumferential groove" and the circumferential groove 2c is referred to as a "second circumferential groove."

[0015] In the illustrated example, five land portions 3 are formed, and land portions 3a and 3b are located in one half in the tire width direction bounded by the tire equatorial plane CL, land portion 3c is located on the tire equatorial plane CL, and land portions 3d and 3e are located in the other half in the tire width direction bounded by the tire equatorial plane CL. Meanwhile, the number of land portions 3 corresponds to the number of circumferential grooves 2, and may be three or more.

[0016] The land portions 3a and 3e, which are the outermost land portions in the tire width direction, are provided with a plurality of widthwise grooves 4 extending in the tire width direction. In the illustrated example, the plurality of widthwise grooves 4 are arranged at approximately equal intervals in the tire circumferential direction in the land portions 3a and 3e, thereby dividing the land portion 3 into a plurality of blocks 5 (of approximately the same shape). Similarly, the land portion 3b adjacent to the land portion 3a on the inner side in the tire width direction and the land portion 3d adjacent to the land portion 3e on the inner side in the tire width direction are also provided with a plurality of widthwise grooves 8 extending in the tire width direction. In the illustrated example, the plurality of widthwise grooves 8 are arranged at approximately equal intervals in the tire circumferential direction in the land portions 3a and 3e, thereby dividing the land portion 3 into a plurality of blocks 9 (of approximately the same shape).

[0017] In the illustrated example, the widthwise grooves 4 and 8 both extend straight, but they may also extend in a zigzag, bent, or curved manner. The widthwise grooves 4 and 8 may extend in the tire width direction, or may extend at an inclination angle of 60° or less (or 45° or less, or 30° or less) with respect to the tire width direction. The groove width (opening width) of the widthwise grooves 4 and 8 may be, for example, 2 mm to 12 mm. The groove depth (maximum depth) of the widthwise grooves 4 and 8 may be, for example, 5 mm to 12 mm. In the illustrated example, the widthwise groove 4 that defines land portion 3a and the widthwise groove 8 that defines land portion 3b are positioned on a substantially extended line, and the widthwise groove 4 that defines land portion 3e and the widthwise groove 8 that defines land portion 3d are positioned on a substantially extended line. This configuration further improves drainage performance. On the other hand, the widthwise grooves 4 that define land portion 3 a and the widthwise grooves 8 that define land portion 3 b do not have to be positioned on a substantially extended line (their imaginary extended lines may be offset from each other in the tire circumferential direction), and the widthwise grooves 4 that define land portion 3 e and the widthwise grooves 8 that define land portion 3 d do not have to be positioned on a substantially extended line (their imaginary extended lines may be offset from each other in the tire circumferential direction). In the illustrated example, the widthwise grooves 4, 8 located in one half of the tire width direction with the tire equatorial plane CL as the boundary and the widthwise grooves 4, 8 located in the other half of the tire width direction are inclined in opposite circumferential directions with respect to the tire width direction, but they may also be inclined in the same circumferential direction with respect to the tire width direction.

[0018] In this way, in the land portions 3 a, 3 b, 3 d, and 3 e, a plurality of blocks 5 and 9 are defined by a plurality of circumferential grooves 2 extending in the tire circumferential direction and a plurality of widthwise grooves 4 and 8 extending in the tire width direction. In the illustrated example, the blocks 5 and 9 have a substantially parallelogram shape in a plan view, but are not limited to this shape.

[0019] As shown in Figure 1, in the land portions 3a, 3e (3b, 3d), a plurality of sipes 6 (10) and a plurality of shallow grooves 7 (11) are provided on the surface of the block 5 (9) so as to extend in opposite directions in the tire width direction with respect to one direction in the tire circumferential direction. The sipes 6 (10) and the shallow grooves 7 (11) intersect with each other.

[0020] In the illustrated example, three sipes 6 (10) are arranged in each block 5 (9). The number of sipes 6 (10) is not particularly limited. In the illustrated example, the three sipes 6 (10) are arranged at equal intervals in the tire circumferential direction so that the block pieces separated by the sipes 6 (10) are approximately the same size. On the other hand, the sipes 6 (10) do not necessarily have to be arranged at equal intervals in the tire circumferential direction. In the illustrated example, the sipes 6 (10) are flat sipes that extend linearly in a plan view, but they may also extend in a zigzag pattern. The sipes 6 (10) may also be so-called three-dimensional sipes, in which the inner wall surface of the sipe is uneven along the sipe depth direction. In this example, one end of the sipe 6 opens into the circumferential groove and the other end communicates with the tread edge TE, but either one or both ends may terminate within the block 5. Furthermore, although both ends of the sipe 10 are open to the circumferential groove 2 , either one or both ends may terminate within the block 9 .

[0021] In this embodiment, the inclination angle θ1 of the sipe 6 (10) with respect to the tire circumferential direction is greater than 0° and less than 90°. The inclination angle θ1 is preferably 45° or greater, more preferably 60° or greater, and even more preferably 75° or greater. In this example, the sipe 6 (10) has the same inclination angle with respect to the tire circumferential direction as the widthwise groove 4 (8), but it can also be different. Here, the "inclination angle" of the sipe or shallow groove means the inclination angle with respect to the tire circumferential direction of an imaginary line connecting the end points of the sipe or shallow groove when the sipe or shallow groove is not linear in plan view. Furthermore, the sipe and shallow groove are measured in the opposite direction to the tire circumferential direction with respect to the tire width direction (see land portion 3d in Figure 1).

[0022] In this example, the sipe depth (maximum depth) of the sipe 6 (10) can be set to, for example, 5 to 8 mm.

[0023] The number of shallow grooves 7 (11) is not particularly limited. In the illustrated example, one end of some of the shallow grooves 7 (11) in the block 5 (9) terminates within the block 5 (9). This ensures the rigidity of the block 5 (9).

[0024] In this embodiment, the inclination angle θ2 of the shallow groove 7 (11) with respect to the tire circumferential direction is greater than 0° and less than 90°. The inclination angle θ2 is preferably 45° or greater, more preferably 60° or greater, and even more preferably 75° or greater.

[0025] The groove width (opening width) of the shallow groove 7 (11) is preferably 0.75 to 1.0 times the sipe width (opening width) of the sipe 6 (10). Although not particularly limited, the groove width (opening width) of the shallow groove 7 (11) can be, for example, 0.3 to 0.4 mm. The groove depth (maximum depth) of the shallow groove 7 (11) is smaller than the depth (maximum depth) of the sipe 6 (10). The groove depth (maximum depth) of the shallow groove 7 (11) can be, for example, 0.1 to 0.3 mm.

[0026] In this embodiment, the difference between the tilt angle θ1 and the tilt angle θ2 is 30° or less (the absolute value of θ1−θ2 is 30° or less). It is also preferable that the difference between the tilt angle θ1 and the tilt angle θ2 is 15° or less.

[0027] In the land portions 3a, 3b, 3d, and 3e, the sipes 6 (10) and the shallow grooves 7 (11) intersect with each other, so that water can be evenly discharged into the sipes 6 (10) and the shallow grooves 7 (11), thereby improving the drainage performance of the tire.

[0028] Next, as for the land portion 3c, as described above, the land portion 3c is provided, which is partitioned by the first circumferential groove 2b extending in the tire circumferential direction and the second circumferential groove 2c extending in the tire circumferential direction. The land portion 3c is formed with a first oblique widthwise groove 12 extending in a first direction inclined with respect to the tire width direction, a second oblique widthwise groove 14 extending in a second direction inclined on the opposite side to the first oblique widthwise groove with respect to the tire width direction, a first sipe 13 extending in the first direction, and a second sipe 15 extending in the second direction. The first oblique widthwise groove 12, the plurality of first sipes 13, the second oblique widthwise groove 14, and the plurality of second sipes 15 are repeatedly formed in the tire circumferential direction.

[0029] In the illustrated example, the first inclined widthwise groove 12 and the second inclined widthwise groove 14 both extend straight, but they may also extend in a zigzag, bent, or curved shape. In the illustrated example, one end of each of the first inclined widthwise groove 12 and the second inclined widthwise groove 14 communicates with the circumferential groove 2, and the other end terminates within the land portion 3c. Therefore, the land portion 3c is a rib-like land portion that is not completely divided into the first inclined widthwise groove 12 and the second inclined widthwise groove 14. In this way, one end of the first inclined widthwise groove 12 and one end of the second inclined widthwise groove 14 terminate within the land portion 3c. Alternatively, the land portion 3c may be a block-shaped land portion. That is, both ends of the first inclined widthwise groove 12 and the second inclined widthwise groove 14 may communicate with the first circumferential groove 2b and the second circumferential groove 2c.

[0030] Furthermore, the first inclined widthwise grooves 12 and the second inclined widthwise grooves 14 preferably extend at an inclination angle of 0 to 45° with respect to the tire width direction. The groove widths (opening widths) of the first inclined widthwise grooves 12 and the second inclined widthwise grooves 14 may be, for example, 2 mm to 12 mm. The groove depths (maximum depths) of the first inclined widthwise grooves 12 and the second inclined widthwise grooves 14 may be, for example, 5 mm to 12 mm.

[0031] In the illustrated example, a linear first sipe portion 121 having a width smaller than that of the first inclined width direction groove 12 is connected to an end of the first inclined width direction groove 12. In addition, a linear second sipe portion 141 having a width smaller than that of the second inclined width direction groove 14 is connected to an end of the second inclined width direction groove 14. In the illustrated example, the first inclined width direction groove 12 communicates with the first circumferential groove 2b, one end of the first sipe portion 121 communicates with the first inclined width direction groove 12, and the other end of the first sipe portion 121 terminates within the land portion 3c without communicating with the second circumferential groove 2c. In addition, the second inclined widthwise groove 14 is connected to the second circumferential groove 2c, and one end of the second sipe portion 141 is connected to the second inclined widthwise groove 14, while the other end of the second sipe portion 141 does not connect to the first circumferential groove 2b and terminates within the land portion 3c.

[0032] The sipe width (opening width) of the first sipe portion 121 and the second sipe portion 141 can be, for example, 0.2 to 0.4 mm. The sipe depth (maximum depth) of the first sipe portion 121 and the second sipe portion 141 can be, for example, 1 to 10 mm. The inclination angles of the first sipe portion 121 and the second sipe portion 141 with respect to the tire width direction can be approximately the same as the inclination angles of the first inclined widthwise grooves 12 and the second inclined widthwise grooves 14 with respect to the tire width direction, respectively, but may be different.

[0033] As shown in FIG. 1 , the first sipes 13 and the second sipes 15 are each disposed at equal intervals in the tire circumferential direction. However, the first sipes 13 and the second sipes 15 do not necessarily have to be disposed at equal intervals in the tire circumferential direction. In the illustrated example, the first sipes 13 and the second sipes 15 are each flat sipes that extend linearly in a plan view, but they may also extend in a zigzag pattern. The first sipes 13 and the second sipes 15 may also be so-called three-dimensional sipes in which the sipe inner wall surfaces are uneven along the sipe depth direction. In this example, both ends of the first sipes 13 and the second sipes 15 open to the circumferential groove 2, but either one or both ends may terminate within the land portion 3c.

[0034] In this embodiment, the inclination angle θ3 of the first sipes 13 and the second sipes 15 with respect to the tire circumferential direction is greater than 0° and less than 90°. The inclination angle θ3 is preferably 45° or greater, more preferably 60° or greater, and even more preferably 75° or greater. In this example, the first sipes 13 and the second sipes 15 may have the same inclination angle with respect to the tire circumferential direction as the first inclined widthwise grooves 12 and the second inclined widthwise grooves 14, respectively, or may have different inclination angles.

[0035] In this example, the sipe depth (maximum depth) of the first sipes 13 and the second sipes 15 can be set to, for example, 5 to 8 mm.

[0036] This tire further includes a plurality of first shallow grooves 16 having a groove depth smaller than the sipe depth of the first sipes 13 and the sipe depth of the second sipes 15, extending in the first direction, and intersecting with the second sipes 15, and a plurality of second shallow grooves 17 having a groove depth smaller than the sipe depth of the first sipes 13 and the sipe depth of the second sipes 15, extending in the second direction, and intersecting with the first sipes 13.

[0037] Although the number of first shallow grooves 16 and second shallow grooves 17 is not particularly limited, it is preferable that two or more of each be arranged continuously in the tire circumferential direction. In the illustrated example, one end of each of the first shallow grooves 16 and second shallow grooves 17 terminates within the land portion 3c. This ensures the rigidity of the land portion 3c.

[0038] In this embodiment, the inclination angle θ4 of each of the first shallow grooves 16 and the second shallow grooves 17 relative to the tire circumferential direction is greater than 0° and less than 90°. The inclination angle θ4 is preferably 45° or greater, more preferably 60° or greater, and even more preferably 75° or greater.

[0039] The groove widths (opening widths) of the first shallow grooves 16 and the second shallow grooves 17 are preferably 0.75 to 1.0 times the sipe widths (opening widths) of the first sipes 13 and the second sipes 15, respectively. Although not particularly limited, the groove widths (opening widths) of the first shallow grooves 16 and the second shallow grooves 17 can each be, for example, 0.3 to 0.4 mm. The groove depths (maximum depths) of the first shallow grooves 16 and the second shallow grooves 17 are each smaller than the depths (maximum depths) of the first sipes 13 and the second sipes 15. The groove depths (maximum depths) of the first shallow grooves 16 and the second shallow grooves 17 can each be, for example, 0.1 to 0.3 mm.

[0040] Here, the magnitude of the difference between the tilt angle θ3 and the tilt angle θ4 is 30° or less (the absolute value of θ3−θ4 is 30° or less).Furthermore, it is preferable that the magnitude of the difference between the tilt angle θ3 and the tilt angle θ4 is 15° or less.

[0041] The effects of the tire of this embodiment will be described below. The tire of this embodiment has, within the land portion 3c, a plurality of sipes (first sipes 13 and second sipes 15) that are inclined in different directions relative to the tire width direction. The first sipes 13 and the first shallow grooves 16 are inclined in opposite directions and intersect with each other, so water can be evenly discharged to the first sipes 13 and the first shallow grooves 16. Similarly, the second sipes 15 and the second shallow grooves 17 are inclined in opposite directions and intersect with each other, so water can be evenly discharged to the second sipes 15 and the second shallow grooves 17. This improves the drainage of the tire. As described above, the tire of this embodiment can improve drainage and grip performance on ice.

[0042] Here, it is preferable that the first shallow grooves 16 and the second shallow grooves 17 do not intersect with each other. In particular, it is preferable that the plurality of first shallow grooves 16 and the plurality of second shallow grooves 17 do not intersect with each other. This is because it is possible to suppress a decrease in uneven wear resistance of the land portion 3c and the occurrence of chipping, which would be caused by a local decrease in rigidity of the portion partitioned by the first shallow grooves 16 and the second shallow grooves 17.

[0043] Furthermore, it is preferable that at least some pairs of the first shallow grooves 16 and the second shallow grooves 17 overlap each other in the tire circumferential direction when projected in the tire width direction (it is preferable that there are pairs of the first shallow grooves 16 and the second shallow grooves 17 that overlap each other in the tire circumferential direction when projected in the tire width direction). This is because the density of the shallow grooves can be increased to further improve drainage performance.

[0044] It is also preferable that the first shallow grooves 16 and the second shallow grooves 17 are arranged so as to be spaced apart when projected in the tire width direction (it is also preferable that there are no pairs of first shallow grooves 16 and second shallow grooves 17 that overlap each other in the tire circumferential direction when projected in the tire width direction). This is because small land portions are partitioned to prevent localized reductions in rigidity, thereby suppressing reductions in uneven wear resistance of the land portions 3c and occurrences of chipping, etc.

[0045] It is preferable that at least some of the first shallow grooves 16 communicate with the first circumferential groove 2b or the second circumferential groove 2c, and / or at least some of the second shallow grooves 17 communicate with the first circumferential groove 2b or the second circumferential groove 2c, because this can further improve drainage.

[0046] It is preferable that at least some of the first shallow grooves 16 among the plurality of first shallow grooves 16 communicate with the plurality of first sipes 13, and / or at least some of the second shallow grooves 17 among the plurality of second shallow grooves 17 communicate with the plurality of second sipes 15. This is because drainage can be further improved.

[0047] It is also preferable that one end of the first inclined widthwise groove 12 and one end of the second inclined widthwise groove 14 terminate within the land portion 3c, because this can improve the rigidity of the land portion 3c.

[0048] It is preferable that the first shallow groove 16 does not extend to a position straddling the first oblique widthwise groove 12 or the second oblique widthwise groove 14. It is also preferable that the second shallow groove 17 does not extend to a position straddling the first oblique widthwise groove 12 or the second oblique widthwise groove 14. It is preferable that the first shallow groove 16 and the second shallow groove 17 are each arranged so as to avoid vent pieces (marks) formed in the tread, as this allows for more efficient drainage.

[0049] At least a portion of the first sipe 13 and the second sipe 15 may be zigzag in plan view.

[0050] It is preferable to use foamed rubber in the tread rubber. Such a configuration can be achieved, for example, by forming the cap rubber layer from foamed rubber, i.e., rubber having many closed cells inside. By forming the cap rubber layer that comes into contact with the road surface from foamed rubber in this way, performance on snow and ice can be improved. Note that foamed rubber can be molded by adding a foaming agent to a normal rubber compound and applying heat and pressure according to a normal tire manufacturing method.

[0051] It is preferable that two or more first shallow grooves 16 are arranged consecutively in the tire circumferential direction. It is also preferable that two or more second shallow grooves 17 are arranged consecutively in the tire circumferential direction.

[0052] [Example of Arrangement of Communication Device] FIG. 2 is a partial cross-sectional view in the tire width direction showing one half in the tire width direction of a pneumatic tire according to one embodiment of the present invention. The tire may include an RF tag as the communication device 100. The RF tag includes an IC chip and an antenna. The RF tag may be arranged, for example, by being sandwiched between multiple components of the same or different types that make up the tire. This makes it easy to attach the RF tag during tire production, and improves the productivity of tires equipped with RF tags. In this example, the RF tag may be arranged, for example, by being sandwiched between a bead filler and another component adjacent to the bead filler. The RF tag may also be embedded in any of the components that make up the tire. This reduces the load applied to the RF tag compared to when the RF tag is sandwiched between multiple components that make up the tire. This improves the durability of the RF tag. In this example, the RF tag may be embedded in a rubber component such as tread rubber or side rubber. It is preferable that the RF tag is not placed at a position that is a boundary between members with different rigidities in the periphery length direction, which is a direction along the tire outer surface in a cross-sectional view in the tire width direction. In this way, the RF tag is not placed in a position where strain is likely to concentrate due to a rigidity difference. Therefore, the load applied to the RF tag can be reduced. This can improve the durability of the RF tag. In this example, it is preferable that the RF tag is not placed at a position that is, for example, a boundary between an end of the carcass and a member adjacent to the end of the carcass (e.g., a side rubber, etc.) in a cross-sectional view in the tire width direction. The number of RF tags is not particularly limited. A tire may be equipped with only one RF tag, or may be equipped with two or more RF tags. Here, an RF tag is described as an example of a communication device, but a communication device other than an RF tag may also be used.

[0053] The RF tag may be disposed, for example, in the tread portion of the tire. In this manner, the RF tag will not be damaged by a side cut of the tire. The RF tag may be disposed, for example, in the tread center portion in the tire width direction. The tread center portion is a position in the tread portion where flexure is less likely to concentrate. In this manner, the load applied to the RF tag can be reduced. This improves the durability of the RF tag. Also, it is possible to prevent differences in communication with the RF tag from both outer sides of the tire in the tire width direction. In this example, the RF tag may be disposed, for example, within a range of 1 / 2 of the tread width centered on the tire equatorial plane in the tire width direction. The RF tag may be disposed, for example, at the tread edge in the tire width direction. If the position of a reader that communicates with the RF tag is predetermined, the RF tag may be disposed, for example, at the tread edge on one side closer to the reader. In this example, the RF tag may be disposed, for example, within a range of 1 / 4 of the tread width in the tire width direction, with the tread edge as the outer end.

[0054] The RF tag may be positioned, for example, closer to the tire cavity than a carcass including one or more carcass plies spanning between bead portions. This configuration makes the RF tag less susceptible to damage from impacts applied from outside the tire or damage such as side cuts or nail penetration. As an example, the RF tag may be positioned in close contact with the surface of the carcass facing the tire cavity. As another example, if there is another component closer to the tire cavity than the carcass, the RF tag may be positioned, for example, between the carcass and another component located closer to the tire cavity than the carcass. An example of another component located closer to the tire cavity than the carcass is an inner liner that forms the tire inner surface. As another example, the RF tag may be attached to the tire inner surface facing the tire cavity. Configuring the RF tag to be attached to the tire inner surface makes it easier to attach the RF tag to the tire and to inspect and replace the RF tag. In other words, the ease of attaching and maintaining the RF tag can be improved. Furthermore, by attaching the RF tag to the inner surface of the tire, it is possible to prevent the RF tag from becoming a nucleus of tire failure, compared to a configuration in which the RF tag is embedded in the tire. Furthermore, when the carcass has multiple carcass plies and there is a position where multiple carcass plies are overlapped, the RF tag may be disposed between the overlapped carcass plies.

[0055] The RF tag may be arranged, for example, in the tread portion of the tire, radially outward of a belt including one or more belt plies. As one example, the RF tag may be arranged radially outward of the belt in the tire radial direction and in close contact with the belt. As another example, if a reinforcing belt layer is provided, the RF tag may be arranged radially outward of the reinforcing belt layer in close contact with the reinforcing belt layer. As another example, the RF tag may be embedded in the tread rubber radially outward of the belt. By arranging the RF tag radially outward of the belt in the tread portion of the tire, communication with the RF tag from the outside of the tire in the tire radial direction is less likely to be obstructed by the belt. Therefore, communication with the RF tag from the outside of the tire in the tire radial direction can be improved. As another example, the RF tag may be arranged radially inward of the belt in the tread portion of the tire. In this way, the outer side of the RF tag in the tire radial direction is covered by the belt, making the RF tag less susceptible to damage from impacts from the tread surface or nail penetration. As one example, the RF tag may be disposed in the tread portion of the tire between the belt and the carcass located radially inward of the belt. Furthermore, if the belt has multiple belt plies, the RF tag may be disposed in the tread portion of the tire between any two belt plies. In this manner, the outer side of the RF tag in the tire radial direction is covered by one or more belt plies, making the RF tag less susceptible to damage from impacts from the tread surface, nail penetration, and the like.

[0056] The RF tag may be disposed, for example, in a sidewall portion or a bead portion of the tire. The RF tag may be disposed, for example, in one sidewall portion or one bead portion that is closer to a reader capable of communicating with the RF tag. This improves communication between the RF tag and the reader. As an example, the RF tag may be disposed between the carcass and the side rubber or between the tread rubber and the side rubber. The RF tag may be disposed, for example, between the tire's maximum width position and the tread surface position in the tire radial direction. This improves communication with the RF tag from the tire's outer side in the tire radial direction compared to a configuration in which the RF tag is disposed radially inward of the tire's maximum width position. The RF tag may be disposed, for example, radially inward of the tire's maximum width position. This allows the RF tag to be disposed near the bead portion, which has high rigidity. This reduces the load applied to the RF tag. This improves durability of the RF tag. As an example, the RF tag may be disposed adjacent to the bead core in the tire radial direction or the tire width direction. Distortion is less likely to concentrate near the bead core. This reduces the load on the RF tag, improving the durability of the RF tag. In particular, it is preferable that the RF tag be positioned radially inward of the tire's maximum width position and radially outward of the bead core of the bead portion. This improves the durability of the RF tag, and communication between the RF tag and a reader is less likely to be obstructed by the bead core, improving the communication performance of the RF tag. Furthermore, when the side rubber is composed of multiple rubber members of the same or different types adjacent in the tire radial direction, the RF tag may be sandwiched between the multiple rubber members that make up the side rubber.

[0057] The RF tag may be disposed sandwiched between a bead filler and a member adjacent to the bead filler. This allows the RF tag to be disposed in a position where strain is less likely to concentrate due to the bead filler. Therefore, the load on the RF tag can be reduced. This improves the durability of the RF tag. The RF tag may be disposed sandwiched between, for example, a bead filler and a carcass. The portion of the carcass that sandwiches the RF tag together with the bead filler may be located on the outer side of the bead filler in the tire width direction, or on the inner side of the bead filler in the tire width direction. When the portion of the carcass that sandwiches the RF tag together with the bead filler is located on the outer side of the bead filler in the tire width direction, the load on the RF tag due to impact or damage from the outside of the tire in the tire width direction can be further reduced. This improves the durability of the RF tag. The bead filler may also have a portion disposed adjacent to a side rubber. In this case, the RF tag may be disposed by being sandwiched between the bead filler and the side rubber. Furthermore, the bead filler may have a portion disposed adjacent to the rubber chafer. In this case, the RF tag may be disposed by being sandwiched between the bead filler and the rubber chafer.

[0058] The RF tag may be arranged, for example, sandwiched between the rubber chafer and the side rubber. In this way, the RF tag can be arranged in a position where the placement of the rubber chafer makes it less likely for distortion to concentrate. This reduces the load on the RF tag. This improves the durability of the RF tag. The RF tag may be arranged, for example, sandwiched between the rubber chafer and the carcass. In this way, it reduces the load on the RF tag due to impacts or damage from the rim. This improves the durability of the RF tag.

[0059] The RF tag may be sandwiched between the wire chafer and another adjacent member on the inner or outer side of the wire chafer in the tire width direction. This makes it difficult for the position of the RF tag to fluctuate when the tire deforms. Therefore, the load applied to the RF tag when the tire deforms can be reduced. This improves the durability of the RF tag. The other adjacent member on the inner or outer side of the wire chafer in the tire width direction may be, for example, a rubber member such as a rubber chafer. Furthermore, the other adjacent member on the inner or outer side of the wire chafer in the tire width direction may be, for example, a carcass.

[0060] A belt reinforcing layer may be further provided on the radially outer side of the belt. For example, the belt reinforcing layer may be formed by winding a cord made of polyethylene terephthalate continuously in a spiral shape in the tire circumferential direction. Here, the cord may be 6.9 x 10 －２ The belt reinforcement layer may be formed by applying an adhesive treatment under a tension of 29.4 N / tex or more, and may have an elastic modulus of 2.5 mN / dtex% or more when measured at 160°C under a load of 29.4 N. Furthermore, the belt reinforcement layer may be arranged to cover the entire belt or only both ends of the belt. Furthermore, the winding density per unit width of the belt reinforcement layer may vary depending on the position in the width direction. By doing so, road noise and flat spots can be reduced without reducing high-speed durability.

[0061] 1: Tread surface, 2: Circumferential groove, 2b: First circumferential groove, 2c: Second circumferential groove, 3: Land portion, 4: Widthwise groove, 5: Block, 6: Sipes, 7: Shallow groove, 8: Widthwise groove, 9: Block, 10: Sipes, 11: Shallow groove, 12: First inclined widthwise groove, 13: First sipe, 14: Second inclined widthwise groove, 15: Second sipe, 16: First shallow groove, 17: Second shallow groove, 100: Communication device

Claims

1. A tire having a land portion defined by a first circumferential groove extending in the tire circumferential direction and a second circumferential groove extending in the tire circumferential direction, wherein the land portion is formed with: a first inclined widthwise groove extending in a first direction inclined with respect to the tire width direction; a second inclined widthwise groove extending in a second direction inclined to the opposite side of the first inclined widthwise groove with respect to the tire width direction; a first sipe extending in the first direction; and a second sipe extending in the second direction, wherein the first inclined widthwise groove, a plurality of the first sipes, the second inclined widthwise groove, and a plurality of the second sipes are repeatedly formed in the tire circumferential direction; and a plurality of first shallow grooves having a groove depth smaller than the sipe depth of the first sipe and the sipe depth of the second sipe, extending in the first direction, and intersecting the second sipes. the tire further comprising a plurality of second shallow grooves having a groove depth smaller than a sipe depth of the first sipes and a sipe depth of the second sipes, extending in the second direction, and intersecting the first sipes.

2. The tire according to claim 1, wherein the first shallow groove and the second shallow groove do not intersect with each other.

3. The tire according to claim 1 or 2, wherein at least some pairs of the first shallow groove and the second shallow groove overlap each other in the tire circumferential direction when projected in the tire width direction.

4. The tire according to claim 1 or 2, wherein the first shallow groove and the second shallow groove are arranged so as to be spaced apart from each other when projected in the tire width direction.

5. A tire described in any one of claims 1 to 4, wherein at least a portion of the plurality of first shallow grooves communicate with the first circumferential groove or the second circumferential groove, or at least a portion of the plurality of second shallow grooves communicate with the first circumferential groove or the second circumferential groove.

6. A tire described in any one of claims 1 to 5, wherein at least a portion of the first shallow grooves among the plurality of first shallow grooves communicate with a plurality of first sipes, or at least a portion of the second shallow grooves among the plurality of second shallow grooves communicate with a plurality of second sipes.

7. A tire according to any one of claims 1 to 6, wherein one end of the first oblique widthwise groove and one end of the second oblique widthwise groove terminate within a land portion.

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